How can I instantiate a Callisto CustomDialog?

See more:

XAML

C#5.0

WinRT

I've got a Callisto CustomDialog in my MainPage.xaml:

<callisto:CustomDialog x:FieldModifier="public" x:Name="GetPhotosetNameCustomDialog"
               Title="Photoset Name"
               removed="Teal" BackButtonVisibility="Visible">
    <StackPanel>
        <TextBlock Margin="0,0,0,8" FontSize="14.6667" FontWeight="SemiLight" TextWrapping="Wrap" Text="Enter a name for the photoset you are creating">
        </TextBlock>
        <TextBlock Margin="0,0,0,8" FontSize="14.6667" FontWeight="SemiLight" Text="Enter your name for acceptance" />
        <!--<callisto:WatermarkTextBox x:Name="txtbxPhotosetName" HorizontalAlignment="Left" Watermark="Enter the photoset name" Width="400" Height="35" />-->
        <TextBox x:Name="txtbxPhotosetName" HorizontalAlignment="Left" PlaceholderText="Enter the photoset name" Width="400" Height="35" />
        <StackPanel Margin="0,20,0,0" HorizontalAlignment="Right" Orientation="Horizontal">
            <Button Content="OK" Width="90" Margin="0,0,20,0" Tapped="PhotosetNamePromptOKTapped" />
            <Button Content="CANCEL" Width="90" />
        </StackPanel>
    </StackPanel>
</callisto:CustomDialog>

But have not found an example for or figured out how to instantiate it. My attempt:

GetPhotosetNameCustomDialog gpncd = new Callisto.Controls.CustomDialog(); // Intellisense gave me this instead of "GetPhotosetNameCustomDialog" is that right?
gpncd.IsOpen = true; // Intellisense gives me nada

That gives me "*'GetPhotosetNameCustomDialog' is a 'field' but is used like a 'type'*"

...and so does this:

GetPhotosetNameCustomDialog gpncd = new GetPhotosetNameCustomDialog();
gpncd.IsOpen = true;

In PhotosetNamePromptOKTapped, I want to retrieve the value in txtbxPhotosetName. Hopefully I can close the CustomDialog then, too, in effect calling gpncd.IsOpen = false;

Maybe my understanding of the usage of the CustomDialog is skewed; without skewering me, is anyone willing to set me straight?